Adapter assembly for precise alignment of fiber optic connectors

Abstract

An adapter assembly is provided for removably receiving two optical fiber ferrules of the type with open grooves extending longitudinally rearward of the end face of the ferrule. The assembly comprises a sleeve with an interior surface that defines a passageway therethrough sized for receiving the ends of the ferrules therein. The interior surface also defines two longitudinal grooves opposite each other that open to the passageway. A guide pin is located in each groove such that an exposed portion of the outer surface of the guide pin along the entire length of the guide pin inside the sleeve is exposed to the passageway. The exposed portion are sized and located relative to each other to slide in the ferrule grooves and operatively align the end faces of the ferrules rotationally and laterally relative to each other when the two ferrules are inserted into the sleeve.

We claim: 
     
       1. An adapter assembly for removably receiving two optical fiber ferrules in an operative coupled relationship, each ferrule containing at least one optical fiber that terminates at an end face of the ferrule, each ferrule defining at least two ferrule grooves extending longitudinally rearward of the end face opposite each other, the adapter assembly comprising: (a) a sleeve having a first open end and a second open end opposite thereto and having an interior surface defining a passageway longitudinally through the sleeve from the first open end to the second open end, the sleeve having an exterior surface, the first open end and the second open end each dimensioned for removably receiving one of the two ferrules therein for operative coupling with the other ferrule inserted opposite thereto in the passageway, the interior surface defining two sleeve grooves extending longitudinally opposite each other;   (b) two guide pins, each guide pin located longitudinally in one of the two sleeve grooves, each guide pin having a length and defining an outer surface along its length, each guide pin mounted in its respective sleeve groove such that an exposed portion of the outer surface of the guide pin along the entire length of the guide pin in the sleeve is exposed to the passageway, the exposed portions of the outer surfaces of the guide pins sized and located relative to each other to slide in the ferrule grooves and operatively align the end faces of the ferrules rotationally and laterally relative to each other when the two ferrules are inserted into the sleeve.   
     
     
       2. The adapter assembly of claim 1 wherein the grooves are coextensive with the passageway. 
     
     
       3. The adapter assembly of claim 2 wherein the cross-section of the grooves is generally the shape of a partial circle of between about 200 degrees and about 300 degrees such that the diameter of the partial circle is greater than the width of the groove at the interior surface and wherein the guide pins have a diameter generally that of the partial circle. 
     
     
       4. The adapter assembly of claim 3 wherein the sleeve is a molded plastic piece, the guide pins are metal, and the guide pins are insert molded in the grooves. 
     
     
       5. The adapter assembly of claim 4 wherein the outer surface of the guide pin that is against the groove is disrupted so that the groove's surface will conform to such disruptions during molding and prevent longitudinal movement of the guide pins. 
     
     
       6. The adapter assembly of claim 1 further comprising an inner block having a mid portion that is generally planar and perpendicular to the sleeve, the mid portion defining a cut-out sized to receive the sleeve extending therethrough, the inner block having two pairs of latch arms extending opposite each other parallel with the sleeve, the latch arms sized and located to engage a connector. 
     
     
       7. The adapter assembly of claim 6 wherein the cut-out is open and the sleeve is laterally inserted therein. 
     
     
       8. The adapter assembly of claim 7 wherein the outer surface of the sleeve defines a reduced cross-section portion at a midpoint along the sleeve and wherein the cross-section of the cut-out has a first portion that is sized to receive the reduced cross-section portion of the sleeve and a second portion through which the sleeve is snap inserted. 
     
     
       9. The adapter assembly of claim 6 further comprising an outer housing in which the inner block and sleeve are located, the outer housing sized to receive connectors therein. 
     
     
       10. The adapter assembly of claim 1 wherein the sleeve has a closed cross-section along its entire length. 
     
     
       11. An adapter assembly for removably receiving two optical fiber ferrules in an operative coupled relationship, each ferrule containing at least one optical fiber that terminates at an end face of the ferrule, each ferrule defining at least two ferrule grooves extending longitudinally rearward of the end face opposite each other, the adapter assembly comprising: (a) a sleeve having a first open end and a second open end opposite thereto and having an interior surface defining a passageway longitudinally through the sleeve from the first open end to the second open end, the passageway sized to receive the two ferrules therein to the extent that a length of the ferrule grooves of each ferrule is disposed inside the passageway when the ferrules are inserted in the sleeve, the sleeve having an exterior;   (b) two guide pins fixedly and permanently mounted in the sleeve parallel to each other and parallel with the passageway and located opposite each other in the passageway, at least a portion of the outer surfaces of each guide pin exposed in the passageway, the portions shaped and located relative to each other to slide in the ferrule grooves of the ferrules and operatively align the end faces of the ferrules rotationally and laterally relative to each other when the two ferrules are inserted into the sleeve.   
     
     
       12. The adapter assembly of claim 11 wherein the guide pins are mounted to the interior surface of the sleeve. 
     
     
       13. The adapter assembly of claim 12 wherein the interior surface defines two grooves extending longitudinally and located generally opposite each other and wherein the guide pins are mounted in the grooves. 
     
     
       14. The adapter assembly of claim 11 wherein the guide pins have a generally cylindrical outer surface and about 180 degrees or less of the outer surface along generally the entire length of the guide pins is exposed in the passageway. 
     
     
       15. The adapter assembly of claim 14 wherein about 180 degrees or more of the outer surface along the generally entire length of the guide pins is located against the sleeve and is disrupted in a radial direction such that when the interior surface of the sleeve conforms to the disruption, the guide pins are positively retained in the longitudinal direction. 
     
     
       16. An adapter and connector assembly comprising: (a) two optical fiber ferrules, each ferrule containing at least one optical fiber that terminates at an end face of the ferrule, each ferrule defining at least two open ferrule grooves extending longitudinally rearward of the end face opposite each other;   (b) a sleeve having a first open end and a second open end opposite thereto and having an interior surface defining a passageway longitudinally through the sleeve from the first open end to the second open end, the ends faces of the ferrules abutted against each other at a point in the passageway such that the two open ferrule grooves of the ferrules are aligned and a length of each ferrule groove disposed inside the passageway, the sleeve having an exterior surface;   (c) two guide pins fixedly and permanently mounted in the sleeve parallel to each other and parallel with the passageway and located opposite each other in the passageway, at least a portion of the outer surfaces of each guide pin exposed in the passageway, the portions shaped and located relative to each other to slide in the ferrule grooves of the ferrules and operatively align the end faces of the ferrules rotationally and laterally relative to each other.   
     
     
       17. The assembly of claim 16 wherein the ferrule has a body portion that tapers radially inward to the end face defining a tapered portion. 
     
     
       18. The assembly of claim 17 wherein the ferrule grooves have a first end beginning in the tapered portion and a second end opposite thereto. 
     
     
       19. The assembly of claim 16 further comprising an inner block that defines a cut-out to receive the sleeve therethrough and having at least two latch arms and further comprising a connector housing in which the ferrule is located and that has engagement features for engaging with the latch arms of the inner block. 
     
     
       20. The assembly of claim 16 wherein the interior surface of the sleeve defines two grooves extending longitudinally and opposite each other and wherein the guide pins are mounted in the grooves. 
     
     
       21. An adapter assembly for removably receiving two optical fiber ferrules in an operative coupled relationship, each ferrule containing at least one optical fiber that terminates at an end face of the ferrule, each ferrule defining at least two ferrule grooves extending longitudinally rearward of the end face opposite each other, the adapter assembly comprising: (a) a sleeve having a first open end and a second open end opposite thereto and having an interior surface defining a passageway longitudinally through the sleeve from the first open end to the second open end, the passageway sized to receive the two ferrules therein to the extent that a length of the ferrule grooves of each ferrule is disposed inside the passageway when the ferrules are fully received in the sleeve, the sleeve having an exterior;   (b) two ribs defined along the interior surface and extending longitudinally parallel with the passageway and protruding radially inward into the passageway, the ribs shaped and located relative to each other to slide in the ferrule grooves of the ferrules and operatively align the end faces of the ferrules rotationally and laterally relative to each other when the two ferrules are inserted into the sleeve.   
     
     
       22. The adapter assembly of claim 21 wherein the ribs are continuous along their length. 
     
     
       23. The adapter assembly of claim 21 wherein the cross-section of the ribs is constant along the length of the ribs. 
     
     
       24. The adapter assembly of claim 21 wherein the sleeve and ribs are one molded piece.